<?xml version='1.0'?> <!--*-nxml-*--> <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- This file is part of systemd. Copyright 2012 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. --> <refentry id="kernel-command-line"> <refentryinfo> <title>kernel-command-line</title> <productname>systemd</productname> <authorgroup> <author> <contrib>Developer</contrib> <firstname>Lennart</firstname> <surname>Poettering</surname> <email>lennart@poettering.net</email> </author> </authorgroup> </refentryinfo> <refmeta> <refentrytitle>kernel-command-line</refentrytitle> <manvolnum>7</manvolnum> </refmeta> <refnamediv> <refname>kernel-command-line</refname> <refpurpose>Kernel command line parameters</refpurpose> </refnamediv> <refsynopsisdiv> <para><filename>/proc/cmdline</filename></para> </refsynopsisdiv> <refsect1> <title>Description</title> <para>The kernel, the initial RAM disk (initrd) and basic userspace functionality may be configured at boot via kernel command line arguments.</para> <para>For command line parameters understood by the kernel, please see <ulink url="https://www.kernel.org/doc/Documentation/kernel-parameters.txt"><filename>kernel-parameters.txt</filename></ulink> and <citerefentry project='man-pages'><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para> <para>For command line parameters understood by the initial RAM disk, please see <citerefentry project='man-pages'><refentrytitle>dracut.cmdline</refentrytitle><manvolnum>7</manvolnum></citerefentry>, or the documentation of the specific initrd implementation of your installation.</para> </refsect1> <refsect1> <title>Core OS Command Line Arguments</title> <variablelist class='kernel-commandline-options'> <varlistentry> <term><varname>systemd.unit=</varname></term> <term><varname>rd.systemd.unit=</varname></term> <term><varname>systemd.dump_core=</varname></term> <term><varname>systemd.crash_chvt=</varname></term> <term><varname>systemd.crash_shell=</varname></term> <term><varname>systemd.crash_reboot=</varname></term> <term><varname>systemd.confirm_spawn=</varname></term> <term><varname>systemd.show_status=</varname></term> <term><varname>systemd.log_target=</varname></term> <term><varname>systemd.log_level=</varname></term> <term><varname>systemd.log_color=</varname></term> <term><varname>systemd.log_location=</varname></term> <term><varname>systemd.default_standard_output=</varname></term> <term><varname>systemd.default_standard_error=</varname></term> <term><varname>systemd.setenv=</varname></term> <term><varname>systemd.machine_id=</varname></term> <listitem> <para>Parameters understood by the system and service manager to control system behavior. For details, see <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>systemd.mask=</varname></term> <term><varname>systemd.wants=</varname></term> <term><varname>systemd.debug-shell</varname></term> <listitem> <para>Additional parameters understood by <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>, to mask or start specific units at boot, or invoke a debug shell on tty9.</para> </listitem> </varlistentry> <varlistentry> <term><varname>systemd.restore_state=</varname></term> <listitem> <para>This parameter is understood by several system tools to control whether or not they should restore system state from the previous boot. For details, see <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> and <citerefentry><refentrytitle>systemd-rfkill.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>. </para> </listitem> </varlistentry> <varlistentry> <term><varname>quiet</varname></term> <listitem> <para>Parameter understood by both the kernel and the system and service manager to control console log verbosity. For details, see <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>debug</varname></term> <listitem> <para>Parameter understood by both the kernel and the system and service manager to control console log verbosity. For details, see <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>-b</varname></term> <term><varname>rd.emergency</varname></term> <term><varname>emergency</varname></term> <term><varname>rd.rescue</varname></term> <term><varname>rescue</varname></term> <term><varname>single</varname></term> <term><varname>s</varname></term> <term><varname>S</varname></term> <term><varname>1</varname></term> <term><varname>2</varname></term> <term><varname>3</varname></term> <term><varname>4</varname></term> <term><varname>5</varname></term> <listitem> <para>Parameters understood by the system and service manager, as compatibility and convenience options. For details, see <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>locale.LANG=</varname></term> <term><varname>locale.LANGUAGE=</varname></term> <term><varname>locale.LC_CTYPE=</varname></term> <term><varname>locale.LC_NUMERIC=</varname></term> <term><varname>locale.LC_TIME=</varname></term> <term><varname>locale.LC_COLLATE=</varname></term> <term><varname>locale.LC_MONETARY=</varname></term> <term><varname>locale.LC_MESSAGES=</varname></term> <term><varname>locale.LC_PAPER=</varname></term> <term><varname>locale.LC_NAME=</varname></term> <term><varname>locale.LC_ADDRESS=</varname></term> <term><varname>locale.LC_TELEPHONE=</varname></term> <term><varname>locale.LC_MEASUREMENT=</varname></term> <term><varname>locale.LC_IDENTIFICATION=</varname></term> <listitem> <para>Parameters understood by the system and service manager to control locale and language settings. For details, see <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>fsck.mode=</varname></term> <term><varname>fsck.repair=</varname></term> <listitem> <para>Parameters understood by the file system checker services. For details, see <citerefentry><refentrytitle>systemd-fsck@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>quotacheck.mode=</varname></term> <listitem> <para>Parameter understood by the file quota checker service. For details, see <citerefentry><refentrytitle>systemd-quotacheck.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>systemd.journald.forward_to_syslog=</varname></term> <term><varname>systemd.journald.forward_to_kmsg=</varname></term> <term><varname>systemd.journald.forward_to_console=</varname></term> <term><varname>systemd.journald.forward_to_wall=</varname></term> <listitem> <para>Parameters understood by the journal service. For details, see <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>vconsole.keymap=</varname></term> <term><varname>vconsole.keymap_toggle=</varname></term> <term><varname>vconsole.font=</varname></term> <term><varname>vconsole.font_map=</varname></term> <term><varname>vconsole.font_unimap=</varname></term> <listitem> <para>Parameters understood by the virtual console setup logic. For details, see <citerefentry><refentrytitle>vconsole.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>udev.log-priority=</varname></term> <term><varname>rd.udev.log-priority=</varname></term> <term><varname>udev.children-max=</varname></term> <term><varname>rd.udev.children-max=</varname></term> <term><varname>udev.exec-delay=</varname></term> <term><varname>rd.udev.exec-delay=</varname></term> <term><varname>udev.event-timeout=</varname></term> <term><varname>rd.udev.event-timeout=</varname></term> <term><varname>net.ifnames=</varname></term> <listitem> <para>Parameters understood by the device event managing daemon. For details, see <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>plymouth.enable=</varname></term> <listitem> <para>May be used to disable the Plymouth boot splash. For details, see <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>luks=</varname></term> <term><varname>rd.luks=</varname></term> <term><varname>luks.crypttab=</varname></term> <term><varname>rd.luks.crypttab=</varname></term> <term><varname>luks.name=</varname></term> <term><varname>rd.luks.name=</varname></term> <term><varname>luks.uuid=</varname></term> <term><varname>rd.luks.uuid=</varname></term> <term><varname>luks.options=</varname></term> <term><varname>rd.luks.options=</varname></term> <term><varname>luks.key=</varname></term> <term><varname>rd.luks.key=</varname></term> <listitem> <para>Configures the LUKS full-disk encryption logic at boot. For details, see <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>fstab=</varname></term> <term><varname>rd.fstab=</varname></term> <listitem> <para>Configures the <filename>/etc/fstab</filename> logic at boot. For details, see <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>root=</varname></term> <term><varname>rootfstype=</varname></term> <term><varname>rootflags=</varname></term> <term><varname>ro</varname></term> <term><varname>rw</varname></term> <listitem> <para>Configures the root file system and its file system type and mount options, as well as whether it shall be mounted read-only or read-writable initially. For details, see <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>systemd.gpt_auto=</varname></term> <term><varname>rd.systemd.gpt_auto=</varname></term> <listitem> <para>Configures whether GPT based partition auto-discovery shall be attempted. For details, see <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>systemd.default_timeout_start_sec=</varname></term> <listitem> <para>Overwrites the default start job timeout <varname>DefaultTimeoutStartSec=</varname> at boot. For details, see <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>modules-load=</varname></term> <term><varname>rd.modules-load=</varname></term> <listitem> <para>Load a specific kernel module early at boot. For details, see <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> </listitem> </varlistentry> <varlistentry> <term><varname>resume=</varname></term> <listitem> <para>Enables resume from hibernation using the specified device. All <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>-like paths are supported. For details, see <citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> </listitem> </varlistentry> </variablelist> </refsect1> <refsect1> <title>See Also</title> <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>dracut.cmdline</refentrytitle><manvolnum>7</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-fsck@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-quotacheck.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-vconsole-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-rfkill.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry> </para> </refsect1> </refentry>